Toner cartridges, in particular those used for copying machines, printers, fax machines, etc, are expensive. Thus it is advantageous to allow the recharging of toner cartridges after the toner powder is consumed. Such recharging saves cost and avoids additional disposal problems.
As show in FIG. 1, a toner cartridge assembly typically comprises a toner hopper 1 for accommodating the toner powder 6, and a feed roller compartment 2 communicating with the toner hopper 1 for dispensing toner power 6 through an opening 4 by a dispensing roller 3. Initially, the toner powder 6 is sealed by a sealing tape 7 of similar means that covers the opening communicating between the toner hopper 1 and the feed roller compartment 2. Before use of the assembly, the sealing tape 7 is removed so the toner powder 6 can fall through the opening to the feed roller compartment 2 to be dispensed. To avoid any leakage of the toner powder 6 from the engaging surfaces of the toner hopper 1 and the feed roller compartment 2, a weld sealing or other types of toner tight sealing method 5 is provided between the hopper 1 and the compartment 2.
In order to recharge the cartridge after the toner powder 6 is used up, the weld is usually destroyed so as to separate the toner hopper 1 and the feed roller compartment 2. The recharging process usually involves at least cleaning the cartridge, refilling it with new toner, and applying a new seal to prevent leakage of the toner powder from the space between the toner hopper and feed roller compartments. Since the originally supplied seal has been cut, a different method of providing this seal to prevent leakage is usually needed. The industry has relied upon felt, foam, or other similar seals, as explained, for example, in prior art U.S. Pat. No. 5,296,902 issued to Michlin.
The Michlin patent contains numerous drawbacks, including at least the requirement for slots and tools to slide the seal in from the side. It is also not convenient to handle and also somewhat complicated in view of its structure and components.
Thus, there is a need for a sealing solution which is simple in both structure and operation.